A387290 Numbers k such that there exist three numbers x, y and z such that k = psi(x) = psi(y) = psi(z) = x + y + z.

241920, 483840, 725760, 967680, 1209600, 1451520, 1693440, 1935360, 2177280, 2419200, 2903040, 3386880, 3628800, 3870720, 4354560, 4838400, 5080320, 5253120, 5806080, 6048000, 6531840, 6773760, 6967296, 7257600, 7741440, 7879680, 8467200, 8709120, 9123840, 9676800

Offset

1,1

Comments

The numbers x, y and z form a psi-amicable triple.

Links

Table of n, a(n) for n=1..30.

S. I. Dimitrov, On psi-amicable numbers and their generalizations, arXiv:2508.02318 [math.NT], 2025.

Example

241920 is in the sequence since 241920 = psi(79170) = psi(80850) = psi(81900) = 79170 + 80850 + 81900.

Crossrefs

Cf. A001615, A137231, A385852, A386901, A386933.

Sequence in context: A281887 A127881 A382285 * A134857 A251007 A078871

Adjacent sequences: A387287 A387288 A387289 * A387291 A387292 A387293

Keyword

nonn

Author

S. I. Dimitrov, Aug 25 2025

Status

approved